Senior Mainframe Developer

**Work Schedule**
Standard (Mon-Fri)
**Environmental Conditions**
Office
**Job Description**
As part of the Thermo Fisher Scientific team, you'll discover meaningful work that makes a positive impact on a global scale. Join our colleagues in bringing our Mission to life every single day to enable our customers to make the world healthier, cleaner and safer. We provide our global teams with the resources needed to achieve individual career goals while helping to take science a step beyond by developing solutions for some of the world's toughest challenges, like protecting the environment, making sure our food is safe or helping find cures for cancer.
We are seeking a
**Senior Mainframe Developer**
to join our Ottawa-based engineering team supporting the development, enhancement, modernization, and production stability of critical applications. This role is ideal for a hands-on mainframe professional who can take ownership of end-to-end delivery, quickly learn complex business and technical domains, lead design discussions, solve production and delivery challenges, and mentor other team members. The successful candidate will bring deep experience with COBOL-based mainframe applications and related technologies, strong analytical and troubleshooting skills, and the ability to partner effectively with business stakeholders, architects, QA, support teams, and global delivery partners. This is a senior role for someone who combines technical depth, strategic solution thinking, accountability, curiosity, and a strong team-first mindset.
**Key Responsibilities**
Lead the design, development, testing, implementation, and maintenance of applications using COBOL, CICS, JCL, VSAM, IDMS and SORT utilities
Own and drive end-to-end delivery of projects, enhancements, defects, and production fixes, ensuring quality, timeliness, and business alignment
Analyze business requirements and translate them into scalable, maintainable, and reliable technical solutions
Prepare technical design documents, impact assessments, implementation plans, data flow analysis, and interface specifications
Collaborate with business stakeholders to understand requirements, identify risks, and propose practical and strategic solutions
Mentor and guide junior and intermediate developers, conduct code reviews, and promote engineering standards and best practices
Act as a trusted technical resource for application knowledge, design guidance, code quality, troubleshooting, and delivery risk management
Lead troubleshooting, root-cause analysis, and resolution of complex production issues, ensuring minimal business impact
Lead or contribute to modernization and integration initiatives, including impact assessment, interface design, data flow analysis, API or middleware integration, and safe migration strategies
Participate in and support release planning, deployment, post-production validation, and operational readiness activities
Participate in an on-call support rotation, including occasional weekends or off-hours
Ensure adherence to development standards, documentation, security, audit, and compliance requirements
Collaborate effectively with global teams, including onshore, offshore, business, QA, infrastructure, architecture, support, and cross-functional partners
Proactively identify risks, dependencies, technical debt, and opportunities to improve system stability, delivery effectiveness, and team capability
**Required Qualifications**
Bachelor's Degree holder with 8+ years of hands-on Mainframe application development experience
Strong hands-on expertise in:
COBOL
CICS
JCL
VSAM
IDMS/DB2
SORT utilities
Excellent understanding of designing and developing applications in Mainframe technologies
Strong experience supporting both batch and online mainframe applications
Strong solutioning mindset with ability to design and implement technical solutions
Demonstrated ownership mindset with the ability to work through ambiguity, proactively identify risks, and drive issues to closure
Ability to quickly learn complex legacy applications, business processes, data flows, and integration points
Willing to provide application support as needed and on rotation
Ability to collaborate with multiple business teams and solve complex issues
Strong analytical and problem-solving abilities
Excellent communication, collaboration, and stakeholder-management skills
Experience with enterprise systems integration
Knowledge of security best practices and compliance requirements
Ability to work independently and as part of a distributed team
Strong team orientation with the ability and willingness to mentor team members and raise overall team capability
**Preferred Qualifications**
Exposure to RPG
Experience with Lotus Notes application development or support
Understanding of API development, integration, or modernization strategies
Experience with MQ, middleware, file-transfer patterns, or enterprise integration approaches
Familiarity with Agile/Scrum methodologies
Experience working inorder management, fulfillment, supply chain, finance, or other high-volume transactional systems
Strong experience in production support and incident management
Experience with tools such as TSO/ISPF, File-AID, Xpediter, Endevor, Changeman, Control-M, CA7, or similar mainframe development and scheduling tools
Experience working with globally distributed teams, including onshore, offshore, and cross-functional delivery partners
**Work Environment**
**Location:**
Ottawa, Canada
**Work Model:**
Hybrid work model with a combination of onsite and remote work, as defined by team and business needs
**Support Expectations:**
Participation in a shared on-call rotation, including occasional weekends or off-hours support
**What Success Looks Like**
The successful candidate will:
Successfully leads projects and delivers high-quality, scalable, and maintainable solutions
Provides effective design solutions aligned with business needs, system architecture, and long-term technology direction
Acts as a technical mentor and go-to person for application knowledge, design guidance, code quality, troubleshooting, and delivery risk management
Demonstrates strong leadership, ownership and accountability in delivery and production support
Engages proactively with business stakeholders and adds value in discussions
Quickly learns complex systems, business processes, and technical dependencies
Identifies risks, technical debt, and improvement opportunities before they become delivery or production issues
Continuously learns, explores new approaches, and drives problem-solving initiatives
Contributes to team success, system stability, and modernization efforts
Supports a positive, collaborative, and team-first culture by sharing knowledge, mentoring others, and helping the team succeed
**Compensation**
The estimated annualized pay range for this position in Ontario is $85,500.00–$114,000.00.
Thermo Fisher Scientific is an EEO/Affirmative Action Employer and does not discriminate on the basis of race, color, religion, sex, sexual orientation, gender identity, national origin, protected veteran status, disability or any other legally protected status.